Auto Loan and Refinance Calculator
Calculate a vehicle payment or compare your current auto loan with a refinance offer.
What this calculator explains
Vehicle price alone does not determine a car payment. Taxes, dealer and registration fees, negative trade equity, financed add-ons, APR and loan term all affect the amount financed and total cost. The calculator shows the amount financed before the monthly payment so a low payment cannot hide a long term or unusually large down payment.
Refinance mode compares the remaining current-loan schedule with a proposed loan and separates monthly cash-flow relief, interest savings, fees and any extension of the payoff date.
How the estimate is calculated
- Calculate net trade equity by subtracting any trade payoff from trade value.
- Add taxable price, entered taxes, fees and financed add-ons.
- Subtract cash down payment and positive trade equity; add negative equity when rolled into the loan.
- Use the amortization formula to calculate payment and total interest.
- For refinancing, compare the remaining current schedule with the proposed new schedule.
- Apply extra payments directly to principal in the simulation.
Formula
Amount financed = vehicle price + taxes + fees + financed add-ons + negative equity − down payment − positive trade equity
Worked example
A $35,000 vehicle with $5,000 down, $2,000 positive trade equity and $3,000 of taxes and fees produces an amount financed of $31,000. At 7% APR for 60 months, the estimated payment is about $613.84 per month before optional products or changes in the first-payment date.
Current rules and configuration notes
- Amount financed includes price, taxes, fees, financed add-ons and negative equity, less down payment and positive trade equity.
- Refinance mode compares the remaining current-loan schedule against the proposed loan; payment reduction and total-cost savings are separate results.
- APR, term and fees must be visible near the monthly payment.
Update requirement: Amortization is evergreen; tax, fee and consumer-guidance content requires periodic review.
Included in the estimate
- Vehicle price, taxes, fees and add-ons
- Down payment and trade equity
- APR, term, payment and total interest
- Negative-equity warning
- Current-versus-refinance comparison
- Extra-payment payoff scenario
Not included or not guaranteed
- A dealer quote or lender approval
- Insurance, maintenance, fuel and depreciation unless modeled separately
- Every state tax rule
- Early payoff penalties unless entered
- A determination of whether an add-on is worthwhile
Frequently asked questions
What is amount financed?
It is the amount borrowed after adding financed taxes, fees and negative equity and subtracting down payment and positive trade equity.
Why is APR important?
APR reflects the annualized borrowing cost disclosed by the lender and can make two loans with similar payments materially different in total cost.
Is a 72- or 84-month loan cheaper?
A longer term can lower the monthly payment but often increases total interest and the time the borrower may owe more than the vehicle is worth.
How does negative equity affect the loan?
If the trade payoff exceeds trade value and the difference is financed, the new loan begins with additional debt unrelated to the new vehicle’s price.
When does auto refinancing make sense?
It may help when the new rate or terms improve the borrower’s goal after fees. Compare total interest and payoff date, not only the monthly payment.
Does making extra payments reduce interest?
Usually, when extra amounts are applied to principal and the contract has no conflicting terms. Confirm how the lender applies additional payments.
Official sources
Applicable period: 2026 · Last reviewed: September 3, 2026
Display the applicable period and a real Last reviewed date beside this source list.
Recommended internal links
Check the payment against your wider budget
Add the proposed car payment to the DTI calculator before signing a longer-term loan.
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